Recently, the technique referred to as VisualHull is used to reconstruct the three dimensional shape of an object included in a multi-viewpoint video from a silhouette image of the object. According to the VisualHull, cross multiply of a plurality of silhouette cones from multiple viewpoints is recognized as the three dimensional shape of the object.
The technique of transmitting drawing differential information from a server to a client, the technique of constructing a three dimensional image from a plurality of two-dimensional images, and the technique of performing matching between a plurality of images to reconstruct three dimensional information have been known (For example, refer to Japanese Laid-open Patent Publication Nos. 2006-236334 and 2000-331160, and Japanese National Publication of International Patent Application No. 11-512856).